US470490A - Draftsman s micrometer-scale - Google Patents

Description

(No Model.) r

E. JONES.

DRAFTSMANS MIGROMETER SCALE. N0. 470,490. Ra tented Mar. 8, 1892.

WITNESSES /N VE N 7'0 wg ATTON Nr'ran .STATES ATENT Orrrcn. I

EDMUND JONES, OF GOLD SPRING HARBOR, NE\V YORK.

D'RAFTSMANS. M lC ROM ETER-SCALE.

SPECIFICATION forming part of Letters Patent No. 470,490, dated March 8, 1892.

. Application filed March 2, 1891.

To all whom, it may concern.-

Be it known that I, EDMUND JONES, a citizen of the United States, residing at Gold Spring Harbor, in the county of Suffolk and State of New York, have invented a new and 'iseful Improvement in Micrometer-Scales, of which the following is a specification. The object of this invention is to provide a nicrometer-scale which is simpler and more ompact in form, more accurate, and more mvenient in use than those heretofore genally employed.

To the end that my invention may be clearly lerstood, I shall omit all preliminary deription and proceed to a detail description rereof, after which I shall distinctly point .ut and claim the invention. Reference is to be had to the accompanying .lrawing, forming a part of this specification, in which the figure is a face view of a micrometer-scale embodying my invention.

The scale thus illustrated as an example is designed to give the thousandths of an inch, and to this end the straight transverse zero-line A is drawn in this instance exactly ten inches in lengtlrand divided into one hundred parts, Which are marked by parallel lines B, crossing the zero-line A at right angles thereto. The lines B extend from the zero-line A in one direction, which We will term downward, to a unit-line 0, parallel to, exactly one inch below, and of the same length as the zero-line A, and upward and beyond the zero-line A to any desired uniform length, preferably about that of the longest lines it is expected to measure with the scale.

Above the zero-line are transverse lines D E F, &c., parallel to and at distances from the zero-line A of, respectively, one, two, three inches, 850., and numbered 1 2 3, 8m, accordingly. The inch-long extensions B B of the two outside sidelinesB below the zeroline A are each divided into ten equal parts, each thus one-tenth of an inch long, marked by points a b c, 850,, and a b c, &c.,respectively. The pairs of points at, b c, c d, d e, ef,f' g, g h, h i, U, andj'lo are consecutively connected by straight lines, which thus intersect the longitudinal lines B obliquely at points whose distance from the zero-line unit extensions 13' 13*.

Serial No. 383,481. (No model) such intersecting lines B are in number distant from said initial points a b c, &c., of the oblique lines. The initial points a b c, &c., are therefore marked O, (1/10,) &c., and the oblique lines a b, b c, &c., at their intersections with the lines B are each marked from 1 to 100, commencing with their initial points a b c, 850., Thus to measure two and six hundred and sixty-six thousandths inches by this scale take off the distance from the intersection of the oblique line marked with the line B, marked 66, on said line B to the transverse line E, marked 2. In asimilar manner a scale may be constructed to measure to any fraction of any unit of length, the distance between the zero-line A and line C being made equal to said unit, the parts B 13 subdivided to give fractions of said unit, and

the transverse space between said extensions tudinal lines B to the desired fraction of the aforesaid fraction, which lines B are inter-' sected by oblique lines connecting consecu tively alternate subdivisions of the extreme The distance between the extreme unit-extensions B B is of course immaterial, save for convenience.

This scale may be etched on glass or metal for a standard by any of the accurate processes in vogue and other scales adjusted therefrom, measurements being taken off the same by dividers or calipers or otherwise.

The dotted lines shown in the drawing illustrate the plan of a scale to measure to tWo-hundredths of an inch, according to my invention.

I claim as my invention Theimproved micrometer-scale herein shown and described for measuring divisions of a unit smaller than a one-hundredth, the same consisting of a plane surface having thereonparallel straight lines A O, &c., said units distance apart, but of equal and as many as ten times said units length, equidistant straight lines B, in number a multiple of ten,

intersecting the lines A O at a right angle the line B and intersecting the lines B 0band subdividing the lines AG into a multiple 1ique1y,as set forth. of ten equal parts, the parts B B of the outside lines B, connecting the ends of the lines 1 EDMUND JONES A 0, being subdivided into ten equal parts, Witnesses:

and straight lines connecting the divisions of CLARENCE L. BURGER,

the line B with the succeeding divisions of ROSOOE G. TOOMBs.

It is hereby certified that in Letters Patent No. 470,490, granted March 8,1892 upon the application of Edmund Jones, of Oold Spring Harbor, New York, foran improvement in Drattsmens Mierometer-Soales, an-error appearsin the printed specification requiring the following correction, viz.: In lines 98 and 99, page 1, the clause and. as many as ten times, should read and many, as ten, times and that the said Letters Patent should be read with this correction therein that same may conform to the recorri of the case in the Patent Office.

Signed, eountersigned, and sealedj this 15th day of March, A. D. 1892.

[ -1 CYRUS BUSSEY,

Assistant Secretary of the Interior.

Letters Patent No.

Oountersigned W. E. SIMONDS,

Commissioner of Patents.

Correction m

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